Double engine transmission



W. F. WILSCN lDOUBLE ENGINE TRANSKISSION oct 19,1948.

2 Shoots-Sheet 1 mea m. 12, 1944 CQ n L o Oct. I9-, 1948. w. F. wlLsN DOUBLE ENGINE TRMSIISSIOI 2 Shoots-Shut 2 rma- Jan..12 ,v 1944 Patented Oct. 19, 1948 William F. Wilson, Wauwatosa, Wis.,

Allis-Chalmers Manufacturing Company,

assignor to Mil- waukee, Wis., a corporation of- Delaware 1 Application January 12, 1944, Serial No. 517,941

(Cl. 'i4-389) Claims.

The invention relates ,to variable speed gearing and it is concerned more specifically with an iinproved automotive type change speed transmission.

The principal object of the invention is to provide an improved double engine transmission, that is, a transmission adapted toreceive power from separate driving engines and having improved change speed gearing for transmitting the combined power of the two engines to a shaft which serves as al single output member of the transmission.

More specifically, it is tion to provide a transmission of the mentioned character having a driving element connectable with one of the driving engines, change speed gearing for selectively establishing die'rent driving connections between said one driving element and the driven shaft, and another driving element connectable with the other engine and cooperating with the change speed gearing so that upon establishment of anyone of the mentioned driving connections the power of both driving engines will be transmitted to the driven shaft through the change speed gearing. In other words, only one change speed gearing, as distinguished from duplicate change speed gearings.-v

will be required for transmitting the combined power of both engines to the driven shaft.

Another object of the invention is to provide a double engine transmission having two driving elements and one change speed gearing, as stated,

an object of the invendrivesmay be selected by means of an extremely simple and practically fool-proof control mechanism.

and in which kthe change speedr lgearing affords l selectively operable high and low speed drives one of which will'be automatically established uponinterruption of the other.

Another object of the .invention is to provide a driving arrangement for the mentioned 'change speeding gearing, including an voverrunning clutch through which the combined power of both engines will be transmitted to the driven shaft for low speed drive, the overrunning clutch l being lockable to permit use of both engines for braking purposes in low gear.

Another object of the invention is to provide a double engine transmission having a lockable overrunning clutch in the low speed drive,- as stated, and a reverse speed drive so arranged that the combined power of both engines will be transmitted through the locked overrunning clutch for rotating the'driven'shaft in reverse.

A further object of the invention 4is to provide a double engine transmission of the mentioned character in which the change speed gearing is so arranged that the high, low and reverse speed A still further object of the invention is to provide an improved change speed transmission vaffording high, low and reverse speed drives.

The mechanism for transmitting power from one of the driving engines to the driven shaft, as contemplated by the invention, preferably comprises a rotatable driving shaft, an idler rotatable about an axis spaced from the axis of rotation of the driving shaft and drivingly connected with the driving shaft, and means for alternately transmitting power to the driven shaft either from the idler or fromthe driving shaft. The

second engine has a driving connection with ther idler, and by establishing a driving connection between the idler and the driven shaft the combined power of both engines will be transmitted to the driven shaft. The idler is preferably loosely mounted on the driven shaft and a jaw clutch' is preferably used for-connecting the idler with and disconnecting Vit from the driven shaft. Engagement of the jaw clutch preferably establishes the high speed drive. Upon disengageyment'of the jaw clutch the power of the second engine is transmitted through the idler to the driving shaft which is connected with the rst engine, and the combined power of both engines may then be transmitted from the driving shaft to the driven shaft through suitable gearing in- `terposed between the driving and driven shafts.

The gearing for transmitting the /combined power I of both engines from the driving shaft to the driven shaft preferably comprises a'loose gear on the driven shaft and an overrunning clutch between said loose gear and the driven shaft, which becomes automatically effective vto establish the.

low speed drive upon disconnection of the driven shaft from the idler by disengagement of the ljawv clutch. The driven member of the overrunning clutch may be prevented-from overrunning its driving member by a suitable locking device which is so arranged that the overrunning clutch can be locked only after the driven shaft has been disconnected from the idler by disengagement of the jaw clutch. 'Ihe provision of a locking device for the overrunning clutch, as contemplated by the invention, has two purposes. One

is to make the braking'power of both engines available, for instance in a motor vehicle, upon establishment of the low speed drive, and the other isl to permit transmission of reverse driving power from the driving shaft to the driven shaft through the locked overrunning clutch. The

loose gear on the driven shaft preferably has a constant mesh driving connection with a reverse idler, and the reverse idler is connectable with and disconnectable from the driving shaft preferably by means of a shiftable selector gear which also serves to control a forward driving connection between the driving shaft and the loose gear on the driven shaft.- When the selector gear is moved into its forward drive establishing position the reverse idler is disconnected from the driving shaft, and when the selector gear is moved into its reverse drive establishing position the forward driving connection between the driving shaft and the loose gear on the driven shaft is interrupted. A mechanism for moving the selector gear and operating the locking device is preferably so arranged that the selector gear may be moved to its forward or reverse drive establishingposition while the overrunning clutch is unlocked, and so that the overrunning clutch may be locked after v the selector gear has been moved either to its forward or to its reverse drive establishing position.

The foregoing and other objects and advantages of the invention will be more fully apparent from the following description of a preferred embodiment of the invention shown in the accompanying drawings. Referring to the drawings, in which like reference characters designate the same or similar parts in the various views:

Fig. 1 is a sectional top view of a transmission along line I-I of Fig. 2;

Fig. 2 is an end view. at a reduced scale, of the transmission shown in Fig. 1;

Fig. 3 is a fragmentary sectional view, at an enlarged scale, on line III-HI of Fig. 1;

Fig. 4 is a sectional top view of a shift mechanism for the transmission shown in Fig. 1;

Fig. 5 is a sectional side view of the shift mech-l anism shown in Fig. 4;

Fig. 6 is a sectional end view of the shift mechanism shown in Fig. 4, taken on line VI-VI of F18. 5;

Fig. 7 is a sectional detail view on line VII-VII of Fig. 6; and

Fig. 8 is a shift diagram for the mechanism shown in Figs. 4 to 6.

Referring to Fig. l, the legend- First engine" is applied to a driving shaft I to indicate that this shaft is to be connected with a driving engine not shown and which may be assumed to be the and the driving shaft I. An adapter 8 surrounding the rearwardly projecting portion 8 of the driving shaft I is bolted to the rear wall 3 of the transmission housing and is suitably flanged for connection with the housing of the torque converter.

The portion of the driving shaft I between the ball bearings 8 and I has a circumferential series of longitudinally extending splines II, and two circumferential grooves I2 and I3 are cut into the splines II. Non-rotatably' connected with the driving shaft I between 'the groove I2 and the ball bearing 'I is a gear or driving wheel I4, the hub of this gear having internal splines matching the splines II, and the gear being retained in an axially'xed position on the shaft I by a snap ring I8 placed into the groove I2 and by a thrust washer I'I interposed between the inner race of the ball bearing l and the hubof the gear I4.

A driven shaft I8 is Journaled in the housing 4 on an axis parallel to the axis of the driving shaft I, a roller bearing I9 for supporting the driven shaft I8 being mounted in the front wall 2 of the housing. and a double row ball bearing 2I for supporting the rear end of the driven shaft being mounted in the rear wall 3 of the housing. Integrally formed with the driven shaft I8 at the forward end thereof outside of the housing 4 is a spiral bevel gear 22 adapted to mesh with a spiral ring gear of a differential mechanism, not shown, it being understood that the transmission as shown in the drawings is intended for use in a tractor having forwardly located propelling gearing including the mentioned differential mechanism.

The driven shaft I8 has axially alined cylindrical and splined portions 23 and 24. respectively, between the bearings I9 and 2i. the diameter of the cylindrical portion 23 being smaller than the outer diameter of the splined portion 24, and a pair of circumferential grooves 26 and 21 are cut into the splines of the portion 24.

Rotatably mounted on the cylindrical portion 23 of the driven shaft I8 is an idler gear 28 having circumferential teeth in mesh with the teeth of the gear wheel I4. The hub of the idler 28 has an axial bore lined with a bushing 29, and the bushing has a running fit on the cylindrical shaft portion 23. A thrust ring 3| surrounds the internal combustion type. lThe shaft I is journaled in front and rear walls 2 and 3 of a housing generally denoted by the reference character 4, a ball bearing 3 supporting the front end of the shaft I being mounted in the front wall 2, and another ball bearing I for supporting the shaft I being mounted in the rear wall 3 of the housing. The shaft I extends rearwardly through the ball bearing I and has a splined portion 8 outside of the housing 4 for connection with the first engine. A hydraulic torque converter (not shown) may be assumed to be interposed between they shaft I and the crankshaft of the first engine, and in conformity with the usual practice a master clutch (not shown) may also be assumed to be interposed between the first engine and the hydraulic torque converter. The driving shaft I is to be alined with the tail shaft of the torque converter and the splined portion 8 is adapted to extend into a hollow internally splined portion of the tail shaft, the external splines of the shaft portion 8 matching the internal splines of the tail shaft to provide a telescopicallyv separable driving connection between the torque converter cylindrical shaft portion at the junction of the splined shaft portion 24 with the cylindrical shaft portion and affords an abutment for limiting forward displacement of the idler relative to the shaft I8. Rearward displacement of vthe idler is limited by a thrust washer 32 interposed between the inner race of the ball bearing 2| and the hub of the idler 28.

The legendfSecond engine in Fig. 1 is applied to a shaft 33 to indicate that this shaft 4is to be connected with another driving engine, not shown, and which, like the ilrst driving engine may be assumed to be of the internal combustion type. A stationary bearing bracket 34 is supported within the housing 4 between the front and rear walls 2 and 3, and ball bearings 38 and 31 mounted in the rear wall 3 and in the bracket 34, respectively, support -the shaft 33 for rotation about an `axis parallel to the axis of the driven shaft I8. The shaft 33 extends rearwardly through the ball bearing 36 and has a splined portion 38 outside of the housing 4 for connection with the second engine. The connection between the shaft 33 and the second engine may beassumed lto be an exact duplicate of the connection between the rst engine and the driving shaft I,

I formed on a clutch collar 48 lwhich is ably connected with the driven shaft I8 and'shiftthe clutch teeth 43' which.' has been generally outlined hereinbefore. That is, .the shaft 33 is to be alined with the tail shaftl of lanother torque converter connected by means of a master-clutch with the second engine, and the splined portion 38 of the shaft 33 is adapted to extend into a hollow internally splined portion of the tail shaft of the second torque converter, the external splines of .the shaft portion 38 matching the internal splines of the .tail shaft to provide a telescopically separable driving connection between the secondmentioned torque converter and the shaft ing the rearwardly projecting Iportion A88 of the shaft 33 is bolted Vto the rear'wall of the housing 4 and is suitably `flanged for connection with the housing of the second mentioned torque converter. Non-rotatably mounted on th-e shaft 33, between' the 'ball bearings 36 and 81, is a gear wheel 33. Anadapter' surround 4I `having circumferential teeth in mesh with the teeth of the idler 28. A rotor pump generally des ignated by the reference character 42 represents auxiliary equipment-which may be driven by .the

i shaft 33. the pump being bolted to the bearing able axially thereof, the clutch collar `internal splines matching the external splines on the portion 24 of the drivenshaft I8. The clutch teeth 44 are adapted to enter into the' gaps between the clutch teeth 43 upon rearward' movement of the clutch collar 48 from the position in which it is yshown in Fig. l, and the mentioned rearward movement of the clutch collar 46 will therefore establish a driving connection between the idler 28 and the driven shaft I8. The clutch a control member, and the the clutch collar when the in driving engagement with will be referred to as a first position of the -control member.

AAssuming that the shafts I and 33 are rotated collar 48 constitutes position occupied by clutch teeth 44 are by the first and second driving engines, respectively, in the same direction, as indi-cated by the arrows A andB in Fig. 2, it will be appa-rent that the idler 28 is then driven by both engines inv the direction of arrow C shown in Fig. vil, and' that upon engagement of the clutch teeth 4 4 with the clutch teeth 43 the combined driving power of both engines will be transmitted to the driven shaft l8. The pitch diameter of the gear I4 is the same as the pitch diameter of the gear 4| and substantially larger .than the pitch diameter of the idler 28, and the drive established by engagement of the clutch teeth 44 with the clutch teeth 43-may be referred to as a high speed drive forward.

- A low speed drive forward and a reverse speed drive are provided for by means of a forward and reverse drive mechanism which is operatively interposed between .the driving Ashaft I and the driven shaft I8. andwhich is constructed as followsf Rotatively loose on the forward portion of the driving shaft I is a forward drive gear 41, this having a smooth axial bore of such diameter provide a running t between the cylindridifferential and torque `are formed on the selector gear cal surface of 'the surface portions of the splines Il. 48 abuts a snap ring 4l placed into the of the shaft IA to limit rearward axial dispiace.. ment of the gear 41, and a thrust washer 5I is interposed be 'ween the gear 41 and .the inner race of the ball bearing 4 to limit forward axial displacement of the gear 41. The shaft I has axial and radial bores 52 for the delivery of lubricant to the running surface of the gear 41 from an oil 'inlet 53 in the rear wall 3 of the housing 4. The

rear face of the gear 41 is recessed and provided with an annular series of internal clutch teeth 54.

Non-rotatably mounted between the gears I4 and 41 is a vselector gear 58 which is movable axially of the shaft I in opposite directions from the positionin which i-t is,-

shown in Fig, 1. The selector gear 58 has a splined axial bore matching the splines Il of the shaft I, and an annular series of clutch teeth 51 facing the forward drive gear 41. The clutch teeth 51 are adapted to enter into the gaps between the clutch teeth 54 upon forward movement of the selector gear 58 from the position in which it is shown in Fig. 1, and such forward movement of the selector gear will therefore establish a driving connection between .the shaft i and the forward drive gear 41. 'I'he position occupied by the selector gear 58 when vthe clutch teeth 51 are in driving engagement with the clutch vteeth 54 will be referred to as a first position of the selector gear.

The forward drive gear 41 on the shaft I meshes with a gear wheel 58 which is rotatively loose on the driven shaft I8, the hub of the gear 58 having a smooth axial bore of such diameter as to provide a running fit between the cylindrical surface of the bore and the outer surface of tbl splined portion24 of the driven shaft I8.

Secured to the web of the gearwheel 58 by an annular series of bolts and nuts 58 is a flanged ring 8l which constitutes the driving member of an overrunning clutch between the gear wheel 584 and the driven shaft I8. A cam ring 82 constituting the driven member of the overrunning clutch is non-rotatably secured vto the driven shaft I8 in rear of the gear wheel 58, the cam ring 82 having a splined axial bore matching the splinesof the shaft portion 24, and a'snap ringr 63 is placed into the groove 26 of the splined shaft portion 24 to limit rearward axial displacement of the cam ring 82. Another snap ring 64 is placed into the groove 21 of the splined shaft portion 24, and a thrust ring 66 bearing against the snap ring 64 affords and cam ring 63. Rearward axial displacement of the gear wheel 58 is limited by contact ofits hub with the front face of the cam ring 82., and

va series of radial oil grooves 51 are cut into theA rear face-of the hub of gear 58.

Referring to Fig. 3, a circumferential series of flats 88 and axial grooves 68 are formed along the periphery of the cam ring 82,and the ring 8l has an internal cylindrical surface radially spaced from the periphery of the cam ring 62.

Rotation of the ring 8| in the direction of arrow i C in Figs. 2 and 3 is transmitted to the cam ring 82 through a series of rollers 1I arranged within the space between the ring 8l and the cam ring 62. The rollers are resiliently urged into the wedging position in which they are'shown in Fig. '3, by a cage 12 and by a helical spring 13 which,` The spring 13 is hooked atV is shown in Fig. 1.

bore and the outer cylindrical A thrust Il!!! groove I3 f on the driving shaft I at the side thereof y y an abutment to limitv forward axial displacement 4of the `gear wheel' 58 The driven shaft I8 has axial and radial bores 14 for the delivery of lubricant from a supply pipe 18 to the running surfaces of the bushing 28 and of the gear 58 on the shaft I8 and also to the radial oil grooves 81 of the gear 88.

Under certain conditions it is necessary, as will be explained hereinbelow, to lock up the overrunning clutch 8|', 82, 1|, and for that purpose locking means for said clutch are provided and comprise an annular series of internal clutch teeth 11 which are formed on a skirt portion of the ring 8|, and another annular series of clutch teeth 18 which are formed on the clutch collar 48 at the end thereof facing the ring 8|. The clutch teeth 18 are adapted to enter into the gaps between the clutch teeth 11 upon forward movement of the clutch collar 48 from the position in which it is shown in Fig. 1,l and such forward movement of the clutch collarV 48 will lock the overrunning clutch. That is, upon movement of the clutch teeth 18 into clutching engagement with the teeth 11 the driven member 82, which as stated is keyed to the shaft I8, will be prevented from overrunning the driving member 6| of the overrunning clutch. 'Ihe position occupied by the clutch collar or control member 48 when the clutch teeth 18 are in clutching engagement with the driven member 8| of the overrunning clutch will be referred to as a second position of the control member.

A reverse idler 18 is rotatably mounted on a stationary shaft 8| which is supported at its forward end within an opening of the front wall 2 of the transmission Ahousing 4. 'I'he rear end of the shaft 8| is supported within a bracket portion 82 of the housing 4 intermediate the front and rear walls 2 and 3. Adjacent to the front wall 2 of the housing the reverse idler 19 has a gear section 83 in constant mesh with the loose gear wheel 58 on the driven shaft I8, the constant mesh relation between the gear section 83 of the reverse idler and the gear 58 being not indicated in Fini but shown in Fig. 2. Adjacent to the bracket portion 82 the reverse idler has another gear section 84 of such pitch diameter that the selector gear 88 may be brought into mesh with the gear section 84 by rearward movement of the selector gear from the position in which it is shown in Fig. 1. 'I'he ,position occupied by the selector gear 58 when it is in mesh with the gear section 84 of the reverse idler will be referred to as a ysecond position of the selector gear.

'I'he axial bore of the reverse idler 19 is lined with a bushing 88, and the stationary shaft 8| has axial and radial bores 81 for the delivery of lubricant from an inlet 88 in the housing wall 2 to the running surfaces of the reverse idler.

When the clutch collar 48 and the selector gear 88 are in the positions in which they are shown in Fig. l the transmission'is in neutral. and movement of the clutch collar to the rear into clutching engagement with the idler 28 establishes the high speed drive, as has been explained hereinbefore. Assuming now that prior. to the movement of the clutch collar 48 into clutching engagement with the idler 28 the selector gear 88 is moved into clutching engagement with the forward drive gear 41, and that the master clutches are held disengaged until the clutch collar 48 is moved into engagement with the idler 28. Upon engagement of the master clutches the transmission will then operate in high, and the gear wheel 58 will be positively drivenin the same direction as the idler 2l but at a lower speed than the shaft I8. and the driven member 82 of the overrunning clutch will overrun its driving member the driven shaft 8|. It should be noted that the pitch diameter of the forward drive gear 41 is substantially smaller than the pitch diameter of the driving gear I4, and .since the gears I4 and 41 rotate at the same speed, under the assumed conditions, it will be obvious that the driven shaft I'8 rotates at a higher speed than the gear wheel 88.

A change from high to low gear may be effected by first disengaging the master clutches, then moving the clutch collar 48 from its real-most position to its neutral position in which it is shown in Fig. l, while the selector gear'88 remains engaged with the forward drive gear 41. and then reengaging the master clutches. The driving power of the first engine will then be transmitted from the driving shaft I through the gears 41, 88, ring 8|, rollers 1I, and cam ring 82 to the driven shaft I8, and the driving power of the second engine will be transmitted from the shaft 88 through the gear 4I, idler 28 and gear I4 to the driving shaft I. 'Ihe combined driving power of both engines will therefore be eective to rotate I8 at low speed.

I If it is desired to retard the tractor by the braking power of the engines while the transmission is in low gear the overrunning clutch must be locked, that is, the cam ring 82 must be prevented from overrunning the arrow C in Fig. 3. This may be accomplished by moving the clutch collar 48 into clutching engagement with the ring 8| as has been explained herelnbefore. In this connection, however, the following should be noted. When the high speed driving connection is interrupted by movement of the clutch collar 48 from its position of engagement with the idler 28 to the position in which it is shown in Fig. 1 the combined power of both engines is automatically shunted to the overrunning clutch, and the rollers 1I are wedged between the cam ring 82 and the ring 8| by the driving torque of the engines. The ring 8| vand the cam ring 82 then rotate in unison, and the position of the ring 8| circumferentially of the shaft I may be such that the clutch teeth 18 do not register with the gaps between the clutch teeth 11, and as a result it would be impossible to move the clutch collar 48 from the position in which itis shown in Fig. 1 forwardly into clutching engagement with the ring 8| while forward driving torque is transmitted to the shaft I8 through the overrunning clutch. However, forward driving torque may be transmitted from the shaft I8 to the clutch collar .48 and to the cam ring 82 of the overrunning clutch upon establishment of the low speed drive, by decelerating the engines momentarily after the vehicle has been accelerated, and during the interval while the vehicle is coasting the clutch collar 48 may readily be moved forwardly into clutching engagement with the ring 8 I. To facilitate engagement of the clutch teeth 18 with the clutch teeth 11, the relatively adjacent ends of the clutch teeth 11 and 18 may be beveled as indicated in Fig. 4.

For reverse speed drive the selector gear 88 is moved into mesh'with the gear section 84 of the reverse idler 18, and the clutch collar 48 is moved into clutching engagement with the ring 8|.

ring 8| in the direction of 'of the'master clutches the Ihese adjustments are made while the master clutches are disengaged, and upon engagement driving power of the first engine will then be transmitted from the driving shaft I through gears 56, 84, 83, 68, ring 6| and clutch collar 46 to the driven shaft I8. and the driving power of the second engine will be transmitted from the shaft 33 through gear 4|, idler 28 and gear I4 to the driving shaft I. The combined driving power of both vengines will therefore be effective to rotate the driven shaft I8 in reverse.

Referring to Figs. 2 and 4 to 7, the mechanism for shifting the clutch collar 46 and theselector gear 56 is constructed as follows: Two shift rods 89 and 9| are slidably mounted in the upper part of the housing 4, the shift rod 89 having rigidly secured thereto a shift fork 92, and the rod 9| having rigidly secured thereto a shift fork 93.

The pronged end of the hift fork 92 embraces the hub of the selector 6 ,1a-groove 94 (Fig. 1) for the reception of the prongs of fork 92 being turned into the hub of gear 56 lin conformity with usual practice. The pronged end of the fork 93 projects into a circumferential groove 96 (Fig. l) of the clutch collar 46 between the clutch teeth 44 and 18. A bracket 91 is mounted in front of the housing 4 on a support 98 connected with the housing wall 2, and a pair of selector rods 99 and |0| are slidably supported in openings of the housing wall 2 and in the bracket 91. The selector rod 99 is connected with the shift rod 89 by an arm |02 secured to the shift rod 89 and having an aperture for the reception of the rear end of the selector rod 99. A screw |03 retains the selector rod 99 against axial displacement relative to the arm |02. The selector rod |0I is connected with the shift rod 9| by an arm |04 secured by a screw |06 to the selector rod 0| and having a bore receiving the reduced forward end of the shift rod 9|. A nut |01 is threaded upon the forward end of the shift rod 9| to secure the arml |04 against displacement axially of the shift rod 9|.

The selector rods 99 and |0I extend forwardly through the bracket 91 into a cap housing |08 mounted on the support 98, and the forward end of the selector rod |0| has notches |09 and III (Fig. 4) facing thel selector rod 99. The selector rod 99 has a similar notch I I2 facing theselector rod |0|. Asshown in Figs. 4, 5 and 6 the notch ||2 accommodates the disk head ||3 of an actuating arm I I4 which is rigidly secured to a shaft I I6 journaled in the lower part of the cap housing |06. The shaft ||6 extends through a bushing ||1 (Fig. '7) press-fitted into a bearing boss |I8 at one side of the cap housing |08, and a reduced end portion of the shaftI I6 (Fig. 6) is journaled in another bearing boss I|9 at the opposite side of the housing |08. Acoil spring |2I surrounding the reduced end portion of the shaft bears against the bearing boss ||9 and against a shoulder on the shaft IIB, to urge the shaft IIB towards the right in Fig. 6. The tendency of the-shaft ||6 to move towards the right under the pressure of spring |2| is communicated to the arm II4 and disk head ||3, and engagement of the disk head with the selector rod 99 limits the movement of the shaft I|6 under the pressure of spring |2I.

Rotatably mounted on the bushing I1 and retained thereon against axial displacement by a bolt |20 is a bracket arm |22, and a hand lever |23 is mounted on a head of the bracket arm |22 for pivotal movement about an axis extending at right angles to the axis of shaft ||6. The hand l0 lever |23 has alined trunnions |24, one of which is shown in Fig. 6, and the trunnions are seated in open-ended bearing notches in' the head of the bracket arm |22. A forked portion at the lower end of the hand lever |23 straddles the outer end of the shaft II6 and is swingably connected therewith by a pivot pin |26. At its upper end the hand lever |23 has a handle |21, and by taking hold of this handle the operator obtains control of the shaft I I6 and actuating arm II4,

fore and aft movement of the handle |21 being eneeuve to rock the shaft Ils about its lexis, and movement of the handle |21 towards the right in Fig. V6 being effective to move the shaft IIB to the left against the pressure of the spring 2I.

The position in which the shift mechanism is I shown in Figs. 4 to 6 corresponds tov the neutral position of the transmission shown in Fig. 1. As shown in Fig. 5, a spring pressed plunger 28 within the bracket 91 engages a notch |29 in the selector rod IOI, and as indicated in Fig. 6. an-

v other spring pressed plunger |3| similarly engages a notch in the selector rod 99. An interlock ball |32 within the bracket 91 is seated in a notch of the selector rod IOI and bears against the selector rod 99, sothat the selector rod I 0| cannot'be moved from the position in which it is shown in Figs. 4 and 5. Accordingly, the clutch collar 46 is positively retained in the position in which it is shown in Fig. 1,whi1e the shift mechanism is in neutral.

In ythe shift diagram shown in Fig. 8 the'position occupied by the handle |21 when the transmission is in neutral is indicatedat N, and from that position the handle |21 may be moved straight forward to the position indicated at LO-I. The result of such movement is that the selector rod 99 is moved to the right in Fig. 4 a suiiicient distance to bringthe notch I I2 opposite to the notch |09, and to bringl another notch |33 in the selector rod 99 opposite to the interlock ball |32. Further, the selector gear 56 is moved into clutching engagement with the forward drive v gear 41 by the mentioned movement of the handle |21 from the position N to the position LO|. The transmission is now in condition for forward drive in low gear and the overrunning clutch is unlocked. When the selector rod 99 arrives in the position corresponding to the position LO-I of the handle |21 the spring pressed plunger I3| (Fig. 6) drops into a notch of the selector bar 99 to retain it in that position.

From the position LO--I the handle |21 may be moved to the' position indicated at HI, such movement first causing axialmovement of the shaft ||6 against the pressure of spring |2I and then rocking movement of the shaft IIB about its axis. As a result of the axial movement of shaft IIB the disk head ||3 of the arm II4 moves from the notch II2 into the notch |09,v and as a result 3 of the rocking movement of the shaft |I6 the clutch collar 46 moves into clutching engagement with the idler 28. The transmission is then in condition for high speed drive forward. The

.' movement of the selector rod IOI to engage the clutch collar 46 with the idler 28 upon engage- 'ment of the selector gear I9 with the forward lock han |32 rides on the fun diameter portion of the selector rod |0| and locks the selector rod 99. As a result, the selector gear 56 is positively retained' in clutching engagement with the forward drive gear 41 when the transmission is in high gear. When the selector rod IDI arrives in the position corresponding to the position HI of the handle |21 the spring pressed plunger |28 drops into a notch |34 of the selector rod IOI to retain it in that position.

From the position HI the handle |21 may be moved to the position LO-2, the first part of.

such movement disengaging the clutch collar 46 from the idler 28 and the second part of this movement engaging the clutch collar 46 with the ring 6I of the overrunning clutch. As explained hereinbefore, the selector gear 56 is in clutching engagement with the yforward drive gear 41 when the handle |21 is at HI, and the first part of the movement of the handle |21 from the position HI towards the position LO-2 in effect places the transmission in low gear, the driving power of both engines being immediately shunted to the overrunning clutch upon disengagement of the clutch collar 46 from the idler 28. The last part of the movement of the handle |21 towards the position LO-2 locks the -overrunning clutch. Movement of the handle |21 from the position HI towards the position LO-2` forces the spring pressed plunger |28 out of the notch |34 of the selector rod I I, and when the handle |21 reaches the middle point M in Fig. 8 the plunger |28 drops into the notch |29. Before proceeding from the point M toward the position LO-2 the operator may accelerate the vehicle and then momentarily decelerate the engines for the purpose explained hereinbefore. When the selector rod |6| arrives in the position corresponding to position LO-2 of the handle |21 the plunger |28 drops into a notch |36 of the selector rod |0| to retain it in said position.

From the position N in Fig. 8 the handle |21 may be moved to the position R in order to establish the reverse speed drive, the movement from N to R first causing rocking movement of the shaft I|6 in one direction, then axial movement against the pressure of spring I2I another rocking movement of the shaft II6 in the opposite direction. The first rocking movement of the shaft |I6 moves the selector gear56 into mesh with the gear section 84 of the reverse idler 19, and also brings the notch II2 of the selector rod 99 opposite to the notch III of the selector rod I6I. Further, the mentioned first rocking movement of the shaft ||6 brings a notch |31 in the selector rod 99 opposite to the interlock ball |32 whereby the selector rod I 0I is released for shifting movement. The selector rod 39 has another notch (not shown) into which the spring pressed plunger |3I (Fig. 6) may enter to retain the selector rod in the position to which it is moved by the first mentioned rocking movement of the shaft I I6.

The axial movement of the shaft I|6 during shift from neutral to reverse brings the disk-head ||3 of the actuating arm I|4 from the notch ||2 into the notch III, and the final rocking movement of the shaft |I6 during the last part of the shift brings the clutch collar 46 into clutching engagement with the driving member 6I of the overrunning clutch. The plunger |28 is forced out of the notch |29 and enters the notch |36 when the selector rod |0| is moved to lock the overrunning clutch upon meshing engagement of the selector gear 56 with the reverse idler 19.

It will be noted that the shift mechanism shown in Figs. 4 to 7 is operable to move the clutch collar or control member 46 either to its first position in which it engages the idler 28, or to and finally and that the shift mechanism is also operable to move the control member 46 to its second position in which it locks the overrunning clutch,

upon movement of the selector gear 66 to its reverse drive establishing position.

In general terms, the transmission vdisclosed herein comprises a driving wheel represented by the gear I4; means including a rotatable driving element represented by the shaft I, for transmitting power from a driving engine to said driving wheel; an idler represented by the idler 28, which is rotatable about an axis spaced from the axis of rotation of said driving element I and which is geared to said driving wheel I4 for rotation thereby under the power of said driving engine in a predetermined direction; means for transmitting power from another driving engine to said idler independently of said driving wheel I4 and operable to rotate said idler under the power of said other driving engine in said predetermined direction, such means being represented by the driving shaft 38 and by the driving gear 4|; a rotatable driven shaft represented by the shaft I8; means selectively operable to establish and interrupt a driving connection between the idler 28 and the driven shaft I 8, such means being represented by the clutch collar 46 and clutch teeth 43 and 44; and driving means operatively interposed between the driving element I, and

the driven shaft I8, such driving means, in the illustrated embodiment of the invention, comprising the selector gear 56, the forward drive gear 41, clutch teeth 54, 51, reverse idler 19, gear 58, overrunning clutch 6|,62, 1|, and lock-up teeth 11, 16 for the over-running clutch.

From a general point of view, it should further be noted that the transmission comprises means for transmitting driving power simultaneously from both driving shafts and 38 at a predetermined speed ratio to the driven shaft |8, such means comprising the driving gears I4, 4I, the idler 28 and the selectively engageable and disengageable clutch teeth 43, 44; and means for transmitting driving power simultaneously from both driving shafts I and 38 to the driven, shaft I8 at another predetermined speed ratio, these latter means comprising the gears I4, 4I and idler 28 in conjunction with means Which-are operable to establish and interrupt a driving connection `between one of the driving shafts I and 38 and the driven shaft I8. In the illustrated embodiment of the invention,

the mentioned means which are operable to establish and interrupt a driving connection between one of the driving shafts and the driven shaft are incorporated in the gearing which comprises the gears 41, v66, 58 and reverse idler 19, the drive afforded by said gearing being controlled by shifting movement of the selector gear 56 into and out of clutching engagement with the drive gear 41, by shifting movement of the selector gear 56 into and out of mesh with the reverse idler 19, by the overrunning clutch 6|,

62, 1I, and by the lock-up clutch 11, 18.

While in the foregoing a preferred embodiment of the invention has been disclosed it should be understood that it is not intended to limit the invention to the exact details of construction herein shown and described for various modifications within the scope of the appended claims may occur to persons skilled in the art.

. mitting power f transmitting power from It is claimed and desired to secure by Letters Patent: l

1.' In a change speed transmission, a driving wheel, means including a rotatable driving4 element for transmitting power from a driving engine to' said driving wheel, an idler rotatable about an axis spaced from the axis of rotation of said driving element and geared to said driving wheel for rotation thereby under the power of said driving engine in a predetermined direction, means for transmitting power from another driving engine to said idler independently of said driving wheel and operable to rotate said idler under the power of said other driving engine in v said predetermined direction,

shaft, means selectively a rotatable driven operable to establish and interrupt a driving connection between 'said idler and said driven shaft, atively interposed between said driving element and said driven shaft selectively operable to rotate said driven shaft either insaid predetermined direction of rotation of said idler or in the opposite direction.

2. In a change speed transmission, a driving wheel, an idler geared to said driving wheel, means including' a driving element rotatable about an axis spaced from the axis of rotation of said idler for transmitting power from a driving engine to'said driving wheel, means for transsaid idler independently of said driving wheel, a rotatable driven shaft, means including relatively engageable and-disengageable drive members operatively interposed between said idler and saidl driven shaft for rotating said driven shaft in a predetermined direction, and means including an overrunning clutch and gearing associated therewith, operatively interposed between said driving element and said driven shaft for rotating said driven shaft in said predetermined direction -u-pon disengagement of said drive members.

3. In a change speed transmission, a driving wheel, an idler geared to said driving wheel, means including a driving element rotatable about an axis spaced from the axis of rotation of said idler for transmitting power from a driving engine. to said driving wheel, means for another driving engine to said idler independently of said driving wheel, a rotatable driven shaft, means including relatively engageable and disengageable drive members operatively interposed between said idler and said driven shaft for rotating said driven shaft in a predetermined direction, means including an overrunning clutch and gearing associated therewith, operatively interposed between said and driving means operfrom another driving engine to -therewith, operatively interposed between said driving element and said driven shaft for drivabout an axis spaced from the axis of rotation y of saididler for transmitting power from a driving engine to said driving wheel. means for transmitting power from another driving engine to said idler independently of said driving wheel, a rotatable driven shaft, means including re1- atively engageable and disengageable drive members for transmitting forward driving power from said idler to said driven shaft, means including an overrunning clutch and disengageable gearing associated therewith for transmitting forward driving power from said driving element to said driven shaft, locking means for said clutch selectively operable to prevent the driven member thereof from overrunning its driving memv ber, and disengageable reverse gearing operatively interposed between said driving element and said driving member of said overrunning clutch, for transmitting reverse driving power to said driven shaft.

6. In a change speed transmission, a pair of rotatable driving shafts adapted, respectively, for connection with separate driving engines, a rotatable driven shaft, constantI mesh gearing drivingly interconnecting said driving shafts, in-

cluding an idler coaxial with and rotatable relative to said driven shaft, a gear wheel rotatively loose on said driven shaft, an overrunning clutch having driving and driven members nondriving element and said driven shaft for rotating said driven shaftI in said predetermined direction upon disengagement of said drive members, and locking means for said clutch selectively operable to prevent the driven member thereof from overrunning its driving member,

4. In a change speed transmission, a driving wheel, an idler geared to said driving wheel,

- means including a driving element rotatable about an axis spaced from the axis of rotation of said idler for transmitting power from a driving engine to said driving wheel, means for transmitting power from another driving engine to said idler independently of said driving wheel,

,a rotatable driven shaft, a driving connection between said idler and said driven shaft including avcontrol element movable into and out of a. drive establishing position, means including an overrunning clutch and gearing associated rotatably connected, respectively, with said gear wheel and with said driven shaft, a control element non-rotatably connected with said driven shaft and shiftable axially thereof into clutching engagement either with said idler or with said driving member of said clutch, and gearing adapted to cooperate with one of said driving shafts and with said gear wheel for rotating said driven shaft upon movement of said control element out of clutching engagement with said idler.

7. In a change speed transmission, a pair of rotatable driving shafts adapted, respectively, for connection with separate driving engines, a rotatable driven shaft, constant mesh ygearing drivingly interconnecting said driving shafts, in-

cluding an idler coaxial with and rotatable relative to said driven shaft, a gear wheel rotatively loose on said driven shaft, an overrunningclutch having driving and driven members non-rotatably connected, respectively, with said gear wheel v and with said driven shaft, a control element non-rotatably connected with said driven shaft and lshiftable axially thereof into clutching engagement either with said idler or with said driving member of said clutch, a disengageable forward drive connection between one of said driving shafts and said gear wheel operable to rotate said driven shaft upon movement of said control element out of clutching engagement with said idler, 'and a disengageable reverse drive connection between one of said driving shafts and said gear wheel operable to rotate said driven shaft connected, respectively, with said gear wheel and with said driven shaft, a control element nonrotatably connected with said driven shaft and shiftable axially thereof into clutching engagement either with said idler or with said driving `member of said clutch, gearing including selector means movable into a rst position for establishing a forward drive connection between one of said driving shafts and said gear wheel and into a second position for establishing a reverse drive connection between one of said shafts and l said gear wheel, and mechanism operable to move said control element into clutching engagement either with said idler or with said driving memberof said clutch upon movement of said selector means intosaid rst position thereof, and to move said control element into clutching engagement with said driving member of said clutch upon movement of said selector means into said second position thereof.

9. A change speed transmission comprising, in combination, a pair of rotatable driving shafts l adapted, respectively, for connection with separate driving engines, a rotatable driven shaft, means for transmitting driving power simultaneously from both of said driving shafts at a predetermined speed ratio to saiddriven shaft, said means comprising a pair of driving gears nonrotatably secured, respectively, to said driving shafts, an idler permanently geared to said driving Sears and rotatively loose on said driven shaft, and selectively engageable and dlsengageable clutch means operativeliy interposed between said idler and said driven shaft; and means for transmitting driving power simultaneously from both of said driving shafts, at another predetermined speed ratio to said driven shaft, said last named means comprising said driving gears and idler in conjunction with means operable to establish and interrupt a driving connection between one of said driving shafts and saiddriven shaft.

10. A change speed transmission as set forth in claim 9 and in-which the means which are operable to establish and interrupt a driving connection between one of said driving shafts and said driven shaft comprise another driving gear rotatively loose on said one driving shaft, selectively engageable and disengageable clutch 'means operatively interposed between said one driving shaft and said other driving gear, and a power transmitting connection between said other driving gear and said driven shaft.

WILLIAM F. WILSON.

REFERENCES CITED The following references are of record in the le of this patent:

y UNITED STATES PATENTS Number 

